Lens-grinding machinery.



C. J. TROPFMAN. LE-N3 GRINDING MACHINERY- Arrucmou FILED we. 23. l9l'8 Patented Jan. 28. 1919.

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3.5 while these parts may be readily assembled in which,-- I

Y i ml is a' fragmental elevation of a g UNITED STATES PATENT OFFICE.

CHARLES J. IROPPMAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO I. A. HARDY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

LENS-GRINDING MACHINERY.

- To all whom it may concern.- I Be it known that I, CHARLES J. Tnorrmm, a citizen of the United States, and a resident of the city of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in lowingis a specification.

" Mypresent invention Lens-GrindingMachinery, of which the folhas relation to imrovements 1n lens grinding mach nery and a's'special reference to the PIOVISIOD. offa- I for permitting the ready attachment vex form, having curvature of different radii upon different merldians and for this reason-the meridians of the lens must be kept in unvarying relation to the meridians of the grinding tool. In such machinery 1 the for holding the meridians of the lens in thei desired relation to the meridians o \the grinding tool has a tendency to ride away and'become detached from the lens supporting block which permits the meridians of the lens to be shifted wlth rela- 'tion-to the meridians of the tool, through the friction of the grinding. TheobJect of my present invention is to provide a sim- -ple,'mexpensive and' easily operable means forjsecurin the lens supporting block to anddetachmg it from the bar for holdmg the meridians of the lens in desired relation to the meridians of the grinding tool so that and disassembled, they will not become disengaged by the action of the machine. I 'attainthe above object by means of the istructure shown in the accompanying drawing head for toric lenses.

ig. 2 is a plan, upon somewhat larger scale than Fig. 1, of the bar for holding thev meridians of the lens in desired relation to the meridians of the rinding tool,

, with my invention embodied t enein.

2; and

Fig.4: is a section on line 44 of Fig. 2. A grinding head for toric lenses, as-shown in Fig. 1, comprises a preferably conical cap isa section on line 33 of Fig.

or head, 5, adapted to assemble and rotate trio bores, prefera rldian to be given the lens, into which ec- Specification of Letters ratent. I 'Paten te an, 28, 1919 Application filed August23,'1918. Serial No. 251,120. v

with a vertically mounted spindle, 6. Through the cap or head, 5, is a transverse bore, 7, which serves as a bearing for a shaft,

8, to the ends of which are rigidly secured brackets, 9, in each of which are clamped,

by means of a washer,'10,"bolt-, 11, and nut,

and with the rods held in the opposite bracket. Arising from the cap or head, 5, 1s a stub column, 14, upon which is secured, so as to rotate therewith, the grinding tool, 15.

A disk shaped lens block, 16, is provided to which the lens, 17, to be ground is cemented by pitch. 18, or with any other suitable substance. The center oftheface of the lens block opposite to the face to which the lens is. secured, is centrally bored. and into this bore is preferably forced a bushmg, 19, of harder metal, having a conical depression therein. This same face 'of the lens block is also provided with two eccenly on the principal mecentric'bores are driven conical headed pins, 20, each of which is provided with an annular groove, "21, just below the conical head.

The meridan holding support comprises a central casting. 22 from diametrically opposite points of which extend rods, 23. The central casting, 22, is centrally bored to' provide a preferably flaring perforation or opening, 24, therethrough, through which is exposed the conical depression in the bushmg, 19, in the back of the lens block. The casting, 22, is also bored to provide holes, 25, through which extend the pins, 20, to a sufficient extent to expose the annular grooves, 21, provided below their conical heads. At a point toone side of the central opening, 24, and preferably on a line midway between the holes, 25, the casting, 22,

screw, 26, around which the central portion of a piece of spring wire, 27, is'loo ed. This is bored and tapped toreceive the headed spring wire is formed so that either arm thereof will extend by and be held yieldingly within the grooves, 21. of the pins, 20, and thereby prevent the accidental withdrawal of these pins from the holes, 25. The ends of the-spring wire are preferably bent to form loops 28, as shown in Fig. 4, so as to affordfinger grips to facilitate the manipulation of the-wire to effect its engagement with and disengagement from the grooves, 21.

The arms, 23, extending from the casting 22, are brought-between the respective pairs; of rods, 13, which, as will be seen, permits" the lens block and lens carried thereby to have all directions of movement, except rotational, with respect to the grinding tool. A rotatable spindle, 29, depends from above the mechanism heretofore described and an arm, 30, carried thereby, having a conical end is brought into engagement with the conical depression in the bushing, 19, in

the back or upper face of the lens block at a point eccentric with the axes of rotation of both thespind1es,,6, and, 29. With ,the lens block held-by the arm, 3O,"eccentr1c to the axis of rotation of the spindle, 6, the rotation of said spindle W111 cause movement between the lens block and the grinding tool, and the eccentric relation of said arm, 30, with the spindle, 29, will mvolve the shifting of the lens block through the rotation of the spindle, 29, so that the path of movement between the lens block. and grinding tool will be constantly changing.

It will now be seen from the foregoing description, taken in connection with the drawing, that I have provided extremely simple means for securing the lens holding block to the grinding head by means of which the engagement and disengagement of the parts can be readily efi'ected, and that a disengagement of these parts through the operation of the machine, orthrough accimechanism having means for maintaining a lens in desired relation to the grinding tool, a lens supporting block provided with annularly grooved pins, said lens maintainlng, means eing provided with perforations for the passage of .said pins and means adapted to yieldingly extend into the grooves in said pins.

2. In combination with lens grinding mechanism having means for maintaining a lens in desired relation to the grinding tool, a lens supporting block provided with transversely slotted pins, said lens maintaining means being provided with perforations for the passage of said pins and a spring mounted upon said means adapted to yieldingly extend into the slots in said pins.

3. In combination with lens grinding mechanism having means for maintaining a lens in desired relation to the grinding tool, a lens holding block, pins. extending therefrom into engagement with said lens maintaining means, and 'a spring latch mounted upon said lens maintaining means and adapted to coact with said pins.

Signed at Chicago, county of Cook and State of-Illinois, this 25th day of July, 1918.

. CHARLES J. TROPPMAN.

Witnesses:

E. O. TRoEGnR, BENJ. T. RovAHotrsE; 

